Anxiolytic Effects Of Neuropeptide S In The Allergic Rhinitis

Alfergic rhinitis (AR) is a common cause of olfactory disorders which generally facilitates anxiety, about 20-30% of adults and 40% of children have been suffered in their life. Neuropeptide S (NPS) has been found to promote olfactory function in mice in our recently studies, and has anxiolytic-like effects in mice and rats reported in several previous researches. However, it is unknown whether the NPS and its receptor (NPSR) system regulate AR-induced anxiety-like behaviors. The aim of present study is to reveal the effect of NPS-NPSR system on the regulation of AR-indued anxiety-like behaviors and the potential mechanisms involved in.Methods:AR in mice was induced by intraperitoneal injection of ovalbumin (OVA) followed by its repeat intranasal instillation. Open field test, elevated plus-maze test and light-dark box test were employed to evaluate AR-induced anxiety behaviors, and the anxiolytic effects of intracerebroventricular (i.c.v.) injection of NPS (0.01-1 nmol) in AR mice. [D-Val5]NPS, a selective NPSR antagonist, was i.c.v. co-injected to investigate the inhibitory effect on NPS.Results:AR induced a increase in the number of sneezing and nasal rubbing in mice. The grooming time was increased in open field test, whereas, the rearing number, the time and distance in the central area were decreased. In elevated plus-maze test, the number of transitions from closed into open arms, the time and distance in the open arms and the total distances were decreased. The time in light box and the number of total transitions between light and dark boxes were also decreased.NPS i.cv. administration in AR mice decreased the grooming time, and increased the rearing number, the time and distance in the central area, and the total distance in open filed, the number of transitions from closed into open arms, and the time in the open arms. NPS also increased the time in light box and transitions in light-dark box.Four and eight nmol of [D-Val5]NPS partially and completely antagonized the anxiolytic effect of NPS (0.1 nmol) in AR mice, respectively.Conclusions:NPS antagonizes AR-induced anxiety-like behavior in mice. The anxiolytic effect of NPS through activation of cognate receptor to enhance olfaction and neural activity in amygdale.